1. FLASH THE ATTACHED KDZ FILE. Go here for instructions on flashing kdz file.
http://forum.xda-developers.com/showthread.php?t=2797190
2. ROOT YOUR DEVICE. Download and copy the prerooted system on your device internal storage. Download LG root and LG Driver from here.
http://forum.xda-developers.com/andr...vices-t3049772 and follow steps 7 8 & 9.
Then type "id" and press enter (no quotes).
You should get back some text starting with "uid=(0)root gid=(0)root".
And then this command,
dd if=/data/media/0/system.rooted.H81510c-EU.img bs=8192 seek=55296 count=529920 of=/dev/block/mmcblk0
wait for the # to appear and type LEAVE to reboot your device.
3.RESTORE SIGNAL. As stated by OP. Download backupimg.zip, extract it then copy the folder backupimg on your device internal storage, DON'T RENAME. Install SSHDROID and busybox from play store on your phone and and download PUTTY application and install it on your pc. Try this link.
http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Run the sshdroid (you need wifi connection). Run putty on your pc, click on ssh and connect your phone by typing the address shown on sshdroid app and then click load.
.After establishing connection a window will open
then copy and paste the following commands.
admin
cd /storage/emulated/0/backupimg/
dd if=aboot.img of=/dev/block/mmcblk0p8
dd if=abootbak.img of=/dev/block/mmcblk0p14
dd if=boot.img of=/dev/block/mmcblk0p38
dd if=factory.img of=/dev/block/mmcblk0p43
dd if=hyp.img of=/dev/block/mmcblk0p6
dd if=hypbak.img of=/dev/block/mmcblk0p12
dd if=laf.img of=/dev/block/mmcblk0p37
dd if=modem.img of=/dev/block/mmcblk0p1
dd if=persist.img of=/dev/block/mmcblk0p23
dd if=pmic.img of=/dev/block/mmcblk0p2
dd if=pmicbak.img of=/dev/block/mmcblk0p10
dd if=raw_resources.img of=/dev/block/mmcblk0p45
dd if=raw_resourcesbak.img of=/dev/block/mmcblk0p46
dd if=rct.img of=/dev/block/mmcblk0p34
dd if=recovery.img of=/dev/block/mmcblk0p39
dd if=rpm.img of=/dev/block/mmcblk0p7
dd if=rpmbak.img of=/dev/block/mmcblk0p13
dd if=sbl1.img of=/dev/block/mmcblk0p3
dd if=sbl1bak.img of=/dev/block/mmcblk0p9
dd if=sdi.img of=/dev/block/mmcblk0p5
dd if=sdibak.img of=/dev/block/mmcblk0p15
dd if=sec.img of=/dev/block/mmcblk0p31
dd if=tz.img of=/dev/block/mmcblk0p4
dd if=tzbak.img of=/dev/block/mmcblk0p11
Then disconnect and reboot your phone twice.